Automatic control of oil dehydrators



Dec. 9, 1,518,792

E. J. HUNT AUTOMATIC CONTROL OF OIL DEHYDRATORS Filed Nov. 4, 1921 4 eets-Sheet 1 &

INVENTO)? BUM/A F/L'I .IHL/A/T.

4 TTORNEY Dec. 9, 1924- 1,518,792

E. J. HUNT AUTOMATIC CONTROL OF OIL DEHYDRATORS Filed Nov. 4, 1921 4 Sheets-Sheet 2 if a INVENTOR 155. SUM/WU JfHL/h/T.

A TTOR/VE Y Dec. 9, 1924- 1,518,792

E. J. HUNT AUTdMATIG CONTROL 01 OIL DEHYDRATORS Filed Nov. 4, 1921 4 ets-$heet 5 ATTORNEY Dec. 9, 192-4- E. J. HUNT AUTOMATIC CONTROL OF OIL DEHYDRATORS Filed Nov. 4, 1921 4 Sheets-Sheet 4 w R Y w m WJ MA 0 M p Mm D E Patented Dec. 9, 1924.

PATENT OFFICE.

EDWARD J. HUNT, OF WEST ORANGE, NEW JERSEY.

AUTOMATIC CONTROII OF OIL DFHYDRATORS.

Application filed November 4, 1921.

tion of the dehydrator as soon as a drop ofwater is condensed.

A further object of my invention is to 7 cause the operation of an audible or a visual signal to give an indication of the presence of moisture.

In the following detailed description I shall refer to the accompanying drawings, in which Figure 1 is a central vertical sectional view of a short-circuiting or resistance-lowering moisture trap; Fig. 2 is a transverse sectional view on the line 22 of Fig. 1 Fig. 3 is a side elevation of an oil dehydratlng apparatus embodyin my in vention and showing the manner 0 connect ing it to atransformer; Fig. 4- is a central vertical sectional view of a modified ,form moisture trap; and Fig. 5 is a diagrammatic view showing the manner of connecting the latter to a transformer casing; and Figs. 7 and 6 are a side elevation and central vertical sectional view respectively of a further modification of the electrodes.

The short-circuiting moisture trap shown in Fig. 1, is placed at the lowest point in the oil circulating system. It comprises a cupshaped casing 3, having inlet and outlet. pipe connections 4 and 5. A solid metal cylinder (51 carried by a stud-bolt 7 constitutes one e ectrode and a hollow concentric metal cyl' inder 8, carried by stud-bolts 9, 10 forms the other electrode, the two being separated by a thin sheath 12 of filter paper which extends below the electrodes to the bottom of the chamber of the casing. I

It is essential that all of the parts of this apparatus shall be absolutely free from,

moisture. Before the parts are assembled, the cylinder 6 is thoroughly dried and is then wrapped in the sheath 12 of filter paper, the ends of the latter being inserted in the recess 15 and held by the key rod 16.

Sept. 21, 1921. and 9 are connected in a circuit 26 with a Serial No. 512,925.

After the wrapped electrode is thoroughly dried in an oven, it is inserted in the cylindrical electrode 8, which fits tightly thereover, the lower portion being provided with several slots, as indicated at 11, to permit the sides to spring inwardly to form a closer fit. The electrodes are then secured to the wooden cover 18 by means of nuts on the bolts 7, 9 and 10. After being again dried in an oven, the electrodes are inserted in the tra casing and secured by screws 19, a cork gas :et 20 ensuring a tight joint. I,

The moisture trap is inserted in the outlet pipe 21 between the transformer casing 23 and the pump 24 connected to the oil dehydrator' 25, in the manner illustrated in Fig. 3. The dehydrator and motor-actuated circulating pump are fully described in my prior application Serial No. 502,258 filed The electrode terminals 7 relay 27. As long as the oil in the transfornier casing i free from moisture, the filter paper 12 will remain dry and will serve as a complete insulatonbetween the electrodes and no current will flow in the circuit 26; but in case any moisture condensesin the transformer and descends into the trap 8 it will be immediately absorbed by the filter paper separator 12, which paper has the peculiar property of giving up the dry oil in the presence of moisture and will then become thoroughly water-soaked, thus lowering the resistance betwen the electrodes 6'and 8 and thereby permittinga flow of current in the circuit 26. This energizes the relay 27 and causes the armature 28 to close the circuit 29, thereby lighting the signal lamp 30 and starting the motor pump 31. The dehydrator is kept in operation until the moisture has been completely removed from the oil in the transformer 23.

In the modification illustrated in Fig. 4, the moisture-absorbing sheet of filter paper 12 is in the form of a disk, which is clamped between an electrode in the form of a bolt 7 having an enlarged disk-like head 7 and another electrode in the form of a hollow cylinder 8? having a clamping disk threaded or otherwise secured to its lower end. The filter paper is centrally perforated to pass over the bolt and is tightly clamped between the two disks 7", 8. The bolt 7 is insulated from the cylinder 8 by a suitable cylindrical filler member 35, which may be of wood, the cylinder being surrounded at its upper end by a wood, cork or other insulating gasket 36, the whole being securely clamped in the cover of the moisture-trap 3 by means of a hollow nut 37 The electrodes are connected to the circuit wires 26 by means of washers which are connected to the respective electrode.

In Fig. 5 I have indicated diagrammatically the manner in which the moisture-trap shown in Fig. 4 may be connected to a transformer which is located at the top of a pole. The trap is connected to a valved outlet or drain-cock at the bottom of the transformer casing. The dehydrator 25 and its attached motor-actuated pump, which constitute a portable unit are carried upon a truck and its inlet and outlet valved connections 32 and 33, are connected by flexible conduits respectively with the outlet cock 40 of the trap and the filler valve 41 of the transformer casing. I prefer to connect the electrodes to a supervisory circuit 26' in the manner indicated in Fig. 5. This may be a single phase current as supplied from the low tension of the pole-type transformer at 220 volts and cycles. When the oil is in good condition, no action whatever will take place but when a slight amount of moisture enters the oil from condensation or otherwise, it will descend to the. bottom of the casing, pass through the drain outlet 21 into the moisture trap 3 where it will be absorbed by the filter paper separator disk 12, resulting in the immediate lowering of the resistance or the short-circuiting of these electrodes. The circuit 26 will therefore be closed through the short-circuited electrodes, thereby energizing the relay 27 which attracts its armature 28, thus closing a shunt around the electrodes through the signal lamp 30. Inasmuch as the relay operates practically instantaneously as soon as the moisture is absorbed by the filter paper between the electrodes the gap between the electrodes is instantly short-circuited and consequently no appreciable current will pass through the paper. No chemical action therefore, can take place and no acids can be formed which would be deleterious. Furthermore, the rela will be held in closed position' by the short circuit through its armature and the lamp will be lighted until a fresh sheet of filter paper is substituted between the electrodes and until the oil in the transformer tank or casing has been filtered by the dehydrator and brought back to normal dry condition. In supplying the newfilter disk, the valve in the drain outlet 21 is, of course, first closed.

In Figs. 6 and 7 I have shown another form of electrodes and holder which may be substituted for those shown in Figs. 1 and 4. In this construction the electrodes 6, 8 arc in the form of plates which are bent to provide supporting shoulders 45 which receive the pressure of the inturned lower ends of spring contacts 7 and 9 depending from the stud-b )lts 7 and 9. The springs thus hold the plates in position and serve as conductors from the electrodes to the stud-bolts. The plates are normally insulated by the filter paper 12. Instead of filter paper I may employ thin sheets of, mica provided with a number of erforations, Normally, the mica se arator lnsula'tes the plates from each other but when moisture is present the water,particles enter the perforations and form a conducting medium between the plates, thus closing the circuit as previously described. In some cases I may even dispense with physical'separators and depend upon a narrow gap maintained between the electrodes.

I claim 1. In a motor-actuated dehydrating device adapted to be connected to an oil container, an electric supply circuit therefor, an

electro-magnetic control device in said cir cuit, a moisture trap having a chamber to entrap any water particles that may be present in the oil, a pair of electrodes connected in circuit with said electro-magnetic device, and a moisture-absorbing medium normally insulating said electrodes, whereby when the presence of moisture impairs the insultating property of said medium an electric current is caused to flow through said electro-magnetic control device.

2. In an apparatus for filtering and dehydrating oil, an oil filtering deviceya motoractuated pump therefore, a container connected to said filtering device having a chamber to entrap water particles contained. in the oil, electrodes within said chamber separated and normally insulated by a moistureabsorbing medium, and an electric circuit connected to said electrodes including means for starting said motor-actuated pump into operation when said electrodes are short-circuited by moisture absorbed by said medium.

3. In an apparatus for filtering and dehydrating oil, an oil filtering device, a motoractuated pump therefor, an electric circuit controlling the operation of said motoractuated pump, electrodes connected in said circuit and normally insulated by a moisture- .absorbing medium, and means for subjecting said medium to any moisture that is present in the oil.

In testimonywhereof I affix my signature.

EDWARD J. HUNT. 

